Expanded Clay Aggregate (ECA ®) can be used as a plant substrate, or in concert with soil in pots, planters, and mulch. It has a number of advantages in this application. First, ECA ® is very light weight, which makes it easier to distribute evenly when mulching, and lowers the weight of pots and planters. It’s also a fantastic insulator, meaning that the delicate roots of plants will be protected from sudden cold snaps, which may otherwise kill them. Finally, ECA ® helps improve soil drainage and provides better oxygenation, which can spur faster and healthier plant growth